1. Technical Field
The present invention relates to collapsible beach chairs and, more particularly, to beach chairs that are sufficiently rigid to provide support when in use and foldable to a conveniently transportable configuration.
2. Discussion of the Prior Art
There are numerous factors to be considered in the design of collapsible beach chairs. First and foremost, the chair must provide sufficient support to be comfortable for the user. In this regard, in many collapsible beach chairs only fabric (such as canvas, or the like) provides support for the human body; for example, the fabric itself may be adapted to attach to posts that can be bored into the sand to support the fabric without supporting the body of the user. The collapsible fabric chairs can be rolled or folded into very small configurations for convenient transport, but the lack of comfort renders these chairs undesirable for many consumers.
Some collapsible beach chairs have rigid mutually pivotable metal frames spanned by plastic or fabric material strips serving as the body support for the user. The rigid metal frames limit the extent to which the chair can be folded for convenient transportability; in particular, the minimum possible size of the folded configuration corresponds to a two level stack comprising the entire chair back at one level and the entire chair seat at the other level. Moreover, it is common experience to have the pivot joints of these chairs clog with sand and become non-functional.
A collapsible chair is disclosed in U.S. Pat. No. 2,001,252 (Johnson) and 2,457,978 (Curran) in which the seat and back are formed from multiple parallel slats joined at their ends. The slats provide sufficient rigidity to effect use comfort, although the unit is somewhat bulky for transport purposes when it is rolled up in its collapsed state. More importantly, sand easily migrates through the slats and into contact with the body of the user, thereby causing irritation and discomfort.
Additional considerations that must be borne in mind for collapsible beach chairs are the ease with which the chair can be collapsed and erected, the ease with which the chair may be carried by a user during transport, and the thermal conductivity of the cover material which must be very low in order to avoid burning the user. In addition, the cover material must be relatively resistant to agglomeration of sand.